Travel bags are divided into hiking bags and daily urban or short distance travel bags, and their functions and purposes are very different. Mountaineering bags can be divided into large bags and small bags. There are two types of large bags: external and internal. Due to the inconvenience of traveling in the mountains and forests, it is generally recommended to use internal travel bags. Taking Siguniang Mountain hiking in Sichuan as an example, it is recommended that men use a 70-80 liter travel bag and women use a 40-50 liter travel bag. It is best to have a detachable top or waist bag with your travel bag. After arriving at the campsite, you can put your commonly used items in the top or waist bag, leave the large bag at the campsite, and go light.